1. State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science; Beijing Normal University; Beijing China
2. Arctic Centre; University of Lapland; Rovaniemi Finland
3. Department of Earth Sciences; Uppsala University; Uppsala Sweden
4. Centre for Ice and Climate, Niels Bohr Institute; University of Copenhagen; Copenhagen Denmark
5. CSC-IT Center for Science Ltd.; Espoo Finland
6. National Oceanography Centre; Liverpool UK